How to Customize Submenu Colors in WinCC OS Project Editor Navigation

Customizing navigation submenu colors by editing '@PTN0.pdl' fails because the WinCC OS Project Editor dynamically manages navigation hierarchies and overwrites '@' system screens during compilation and runtime initialization. In standard PCS 7 systems, navigation bar and submenu colors are governed by the global WinCC Design Style and the OS Project Editor palette configuration. To change submenu colors permanently, configure the central color palette in Computer Properties -> User Interface and Design, or select a custom layout scheme within the OS Project Editor.

Role of OS Project Editor and System PDL Architecture

In SIMATIC PCS 7 Operator Stations (OS), screen hierarchy and navigation bars are generated automatically by the OS Project Editor based on the Plant View configured in SIMATIC Manager.

The generated navigation system comprises several standardized picture files stored in the GraCS directory:
* @Overview1.pdl / @Overview.pdl: Top-level overview bar containing plant area buttons and alarm status indicators.
* @PTN0.pdl (Picture Tree Navigation): System screen responsible for rendering dynamic submenu drop-down trees and child picture selection buttons.
* @Buttons11.pdl / @Buttons12.pdl: Standard runtime button bars.

These screens are prefixed with the @ symbol, designating them as protected system files managed by the PCS 7 system generator rather than static user graphics.

Why Editing @PTN0.pdl Fails in Runtime

Engineers often attempt to alter submenu styling by opening @PTN0.pdl directly in WinCC Graphics Designer and modifying object background colors or font styles. However, upon launching WinCC Runtime, the navigation submenus revert to the default gray appearance.

This behavior occurs because:
1. Dynamic Script-Driven Instantiation: Submenu buttons inside @PTN0.pdl are not static UI elements. They are dynamically generated, positioned, and colored at runtime by internal C/VBS scripts (SSM - Standard Screen Management) and the Picture Tree Manager.
2. Central Design Theme Enforcement: WinCC enforces global design styles (e.g., WinCC Classic, WinCC Dark, or SIMATIC Standard). Object properties defined by the global design override static color attributes assigned to individual PDL objects.
3. OS Project Editor Overwrite: Whenever the OS Project Editor is executed—or during complete OS project downloads—system screens beginning with @ are re-extracted from system template libraries, completely overwriting manual modifications.

Correct Methods to Customize Submenu Colors

To achieve persistent visual customization without breaking PCS 7 standard screen management, use the supported design workflows:

Method 1: Modify Global Design Style and Color Palette

Open the project in WinCC Explorer.
Right-click the computer object in the tree and select Properties.
Navigate to the User Interface and Design tab.
Under Active Design, review the selected style:
* Switching between designs (e.g., WinCC Classic vs. WinCC Modern) updates the overall tone of menu buttons and borders.
Under Color Scheme / Palette:
* Inspect the active palette. Customizing color indices in the project palette allows navigation elements that reference palette color IDs to inherit new theme colors automatically.

Method 2: Configure Layout Schemes in OS Project Editor

In WinCC Explorer, double-click OS Project Editor.
Select the Layout tab.
Choose the appropriate screen layout resolution and scheme (e.g., SIMATIC Standard 1920x1080 or specialized widescreen layouts).
Select the Basic Data tab. Ensure that custom templates are preserved or apply the standardized APL palette update.
Click OK to regenerate the navigation system cleanly with the updated layout configuration.

Verification

Launch WinCC Runtime on the OS station.
Click on plant hierarchy area buttons in the navigation overview bar.
Confirm that drop-down submenus expand smoothly and display the customized color styling, text contrast, and active hover states.
Execute a test run of the OS Project Editor and verify that menu styling is preserved without reverting to unwanted defaults.

Limitations and Operational Precautions

Never set individual object colors inside @PTN0.pdl or @Overview1.pdl manually; doing so creates maintenance overhead and will be erased during the next PCS 7 software update or project editor run.
Ensure high contrast between submenu background colors and navigation button fonts to maintain compliance with industrial ergonomic standards (such as ISO 9241 and ISA-101).
In multi-client systems, custom design palettes must be applied consistently across all OS Clients to maintain uniform operator experience.

Engineer FAQ

Can I replace @PTN0.pdl with a completely custom navigation menu?
While technically possible, replacing the Picture Tree Navigator breaks native PCS 7 area-specific alarm aggregation and picture hierarchy navigation. It is strongly discouraged in standard PCS 7 installations.
Why are files prefixed with '@' locked or overwritten?
The @ prefix is reserved by Siemens for files managed dynamically by system compilers and editors. Any changes to @ files are treated as temporary runtime artifacts.
How does WinCC handle high-contrast themes for control rooms?
WinCC provides pre-engineered high-contrast and dark-mode styles within the User Interface and Design settings, eliminating the need to edit individual PDL files.

Technical References

SIMATIC PCS 7 OS Process Control System; Graphic Objects and Screen Management Manual.
SIMATIC WinCC V7/V8 Graphics Designer and UI Design Guide.
Siemens Industry Online Support Entry ID 109801081: Customizing Screen Layouts and Design Themes in PCS 7.